Although applicable to any desired structural components and aircraft or spacecraft, the present invention and the set of problems on which it is based are described in greater detail in relation to a fuselage structure of an aircraft.
Carbon-fibre-reinforced plastics material (CFRP) fuselage structures generally consist of planar members, in particular skin members, which are shaped in the manner of a tube. The planar members are reinforced internally in the longitudinal and peripheral direction by reinforcing members, in particular stringers and formers. The reinforcement members provide the required stability and rigidity, taking a considerable proportion of the loads.
Modern CFRP fuselage structures generally reflect the construction of older metal fuselage structures. Because of the very different material properties, this approach leads to high manufacturing costs for CFRP fuselage structures. The high manufacturing costs result in particular from the fact that the methods used to manufacture the metal fuselage structures are not really applicable to a fibre composite material, in particular a thermosetting one Moreover, these “black metal” fuselage structures cannot fully exploit the typical advantages of anisotropic fibre composite materials, since they evolved from isotropic metals. For example, mass-produced parts, such as angle brackets, clips or the like, cannot really be made cost-effectively from fibre composite material.
Further, sandwich constructions are used in the field of aviation, and are formed from an upper and a lower cover layer between which a honeycomb core structure is located to increase the rigidity. As an alternative to the honeycomb core structure, it has also become known to form the core structure from a rigid foamed material. As regards the thermal and acoustic insulation and the component manufacture, inter alia, the use of rigid foamed materials of this type has advantages over the use of honeycomb core structures. The poor mechanical properties by comparison with the honeycomb core structures are a drawback of the rigid foamed material core structures. Stitching processes, in which fibres are introduced into the cover layers and the rigid foamed foam, are used to compensate for these poor mechanical properties. After a resin infiltration process, the fibres which are embedded in the resin contribute to the mechanical reinforcement of the rigid foamed material, the fibres, along with the resin, forming what are known as “pins”. A method of this type is disclosed for example in DE 10 2005 024 408 A1.
The use of sandwich constructions, as described above, is already a first step towards producing components which exploit the specific material properties of fibre composite materials. Currently, however, there are still no adequate solutions available which provide a structural component comprising a planar member and comprising a reinforcing member reinforcing said planar member, and which simultaneously exploit the specific material properties of fibre composite materials.